1 -- -----------------------------------------------------------------------------
3 -- (c) The University of Glasgow, 2005-2007
5 -- Running statements interactively
7 -- -----------------------------------------------------------------------------
10 -- The above warning supression flag is a temporary kludge.
11 -- While working on this module you are encouraged to remove it and fix
12 -- any warnings in the module. See
13 -- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
16 module InteractiveEval (
18 RunResult(..), Status(..), Resume(..), History(..),
19 runStmt, SingleStep(..),
27 setContext, getContext,
28 nameSetToGlobalRdrEnv,
38 compileExpr, dynCompileExpr,
40 Term(..), obtainTerm, obtainTerm1, obtainTermB, reconstructType,
41 skolemiseSubst, skolemiseTy
47 #include "HsVersions.h"
49 import HscMain hiding (compileExpr)
52 import Type hiding (typeKind)
53 import TcType hiding (typeKind)
55 import Var hiding (setIdType)
58 import Name hiding ( varName )
75 import RtClosureInspect
81 import Data.List (find)
87 import Control.Exception as Exception
88 import Control.Concurrent
89 import Data.List (sortBy)
91 import Foreign.StablePtr
93 -- -----------------------------------------------------------------------------
94 -- running a statement interactively
97 = RunOk [Name] -- ^ names bound by this evaluation
98 | RunFailed -- ^ statement failed compilation
99 | RunException Exception -- ^ statement raised an exception
100 | RunBreak ThreadId [Name] (Maybe BreakInfo)
103 = Break Bool HValue BreakInfo ThreadId
104 -- ^ the computation hit a breakpoint (Bool <=> was an exception)
105 | Complete (Either Exception [HValue])
106 -- ^ the computation completed with either an exception or a value
110 resumeStmt :: String, -- the original statement
111 resumeThreadId :: ThreadId, -- thread running the computation
112 resumeBreakMVar :: MVar (),
113 resumeStatMVar :: MVar Status,
114 resumeBindings :: ([Id], TyVarSet),
115 resumeFinalIds :: [Id], -- [Id] to bind on completion
116 resumeApStack :: HValue, -- The object from which we can get
117 -- value of the free variables.
118 resumeBreakInfo :: Maybe BreakInfo,
119 -- the breakpoint we stopped at
120 -- (Nothing <=> exception)
121 resumeSpan :: SrcSpan, -- just a cache, otherwise it's a pain
122 -- to fetch the ModDetails & ModBreaks
124 resumeHistory :: [History],
125 resumeHistoryIx :: Int -- 0 <==> at the top of the history
128 getResumeContext :: Session -> IO [Resume]
129 getResumeContext s = withSession s (return . ic_resume . hsc_IC)
136 isStep RunToCompletion = False
141 historyApStack :: HValue,
142 historyBreakInfo :: BreakInfo,
143 historyEnclosingDecl :: Id
144 -- ^^ A cache of the enclosing top level declaration, for convenience
147 mkHistory :: HscEnv -> HValue -> BreakInfo -> History
148 mkHistory hsc_env hval bi = let
149 h = History hval bi decl
150 decl = findEnclosingDecl hsc_env (getHistoryModule h)
151 (getHistorySpan hsc_env h)
154 getHistoryModule :: History -> Module
155 getHistoryModule = breakInfo_module . historyBreakInfo
157 getHistorySpan :: HscEnv -> History -> SrcSpan
158 getHistorySpan hsc_env hist =
159 let inf = historyBreakInfo hist
160 num = breakInfo_number inf
161 in case lookupUFM (hsc_HPT hsc_env) (moduleName (breakInfo_module inf)) of
162 Just hmi -> modBreaks_locs (getModBreaks hmi) ! num
163 _ -> panic "getHistorySpan"
165 getModBreaks :: HomeModInfo -> ModBreaks
167 | Just linkable <- hm_linkable hmi,
168 [BCOs _ modBreaks] <- linkableUnlinked linkable
171 = emptyModBreaks -- probably object code
173 {- | Finds the enclosing top level function name -}
174 -- ToDo: a better way to do this would be to keep hold of the decl_path computed
175 -- by the coverage pass, which gives the list of lexically-enclosing bindings
177 findEnclosingDecl :: HscEnv -> Module -> SrcSpan -> Id
178 findEnclosingDecl hsc_env mod span =
179 case lookupUFM (hsc_HPT hsc_env) (moduleName mod) of
180 Nothing -> panic "findEnclosingDecl"
182 globals = typeEnvIds (md_types (hm_details hmi))
184 find (\id -> let n = idName id in
185 nameSrcSpan n < span && isExternalName n)
186 (reverse$ sortBy (compare `on` (nameSrcSpan.idName))
190 -- | Run a statement in the current interactive context. Statement
191 -- may bind multple values.
192 runStmt :: Session -> String -> SingleStep -> IO RunResult
193 runStmt (Session ref) expr step
195 hsc_env <- readIORef ref
197 breakMVar <- newEmptyMVar -- wait on this when we hit a breakpoint
198 statusMVar <- newEmptyMVar -- wait on this when a computation is running
200 -- Turn off -fwarn-unused-bindings when running a statement, to hide
201 -- warnings about the implicit bindings we introduce.
202 let dflags' = dopt_unset (hsc_dflags hsc_env) Opt_WarnUnusedBinds
203 hsc_env' = hsc_env{ hsc_dflags = dflags' }
205 maybe_stuff <- hscStmt hsc_env' expr
208 Nothing -> return RunFailed
209 Just (ids, hval) -> do
211 withBreakAction (isStep step) dflags' breakMVar statusMVar $ do
213 let thing_to_run = unsafeCoerce# hval :: IO [HValue]
214 status <- sandboxIO dflags' statusMVar thing_to_run
216 let ic = hsc_IC hsc_env
217 bindings = (ic_tmp_ids ic, ic_tyvars ic)
221 traceRunStatus expr ref bindings ids
222 breakMVar statusMVar status emptyHistory
224 handleRunStatus expr ref bindings ids
225 breakMVar statusMVar status emptyHistory
228 emptyHistory = nilBL 50 -- keep a log of length 50
230 handleRunStatus expr ref bindings final_ids breakMVar statusMVar status
233 -- did we hit a breakpoint or did we complete?
234 (Break is_exception apStack info tid) -> do
235 hsc_env <- readIORef ref
236 let mb_info | is_exception = Nothing
237 | otherwise = Just info
238 (hsc_env1, names, span) <- bindLocalsAtBreakpoint hsc_env
241 resume = Resume expr tid breakMVar statusMVar
242 bindings final_ids apStack mb_info span
244 hsc_env2 = pushResume hsc_env1 resume
246 writeIORef ref hsc_env2
247 return (RunBreak tid names mb_info)
248 (Complete either_hvals) ->
250 Left e -> return (RunException e)
252 hsc_env <- readIORef ref
253 let final_ic = extendInteractiveContext (hsc_IC hsc_env)
254 final_ids emptyVarSet
255 -- the bound Ids never have any free TyVars
256 final_names = map idName final_ids
257 Linker.extendLinkEnv (zip final_names hvals)
258 hsc_env' <- rttiEnvironment hsc_env{hsc_IC=final_ic}
259 writeIORef ref hsc_env'
260 return (RunOk final_names)
263 traceRunStatus expr ref bindings final_ids
264 breakMVar statusMVar status history = do
265 hsc_env <- readIORef ref
267 -- when tracing, if we hit a breakpoint that is not explicitly
268 -- enabled, then we just log the event in the history and continue.
269 (Break is_exception apStack info tid) | not is_exception -> do
270 b <- isBreakEnabled hsc_env info
274 let history' = mkHistory hsc_env apStack info `consBL` history
275 -- probably better make history strict here, otherwise
276 -- our BoundedList will be pointless.
278 status <- withBreakAction True (hsc_dflags hsc_env)
279 breakMVar statusMVar $ do
281 (do putMVar breakMVar () -- awaken the stopped thread
283 (takeMVar statusMVar) -- and wait for the result
284 traceRunStatus expr ref bindings final_ids
285 breakMVar statusMVar status history'
289 handle_normally = handleRunStatus expr ref bindings final_ids
290 breakMVar statusMVar status history
293 isBreakEnabled :: HscEnv -> BreakInfo -> IO Bool
294 isBreakEnabled hsc_env inf =
295 case lookupUFM (hsc_HPT hsc_env) (moduleName (breakInfo_module inf)) of
297 w <- getBreak (modBreaks_flags (getModBreaks hmi))
298 (breakInfo_number inf)
299 case w of Just n -> return (n /= 0); _other -> return False
304 foreign import ccall "&rts_stop_next_breakpoint" stepFlag :: Ptr CInt
305 foreign import ccall "&rts_stop_on_exception" exceptionFlag :: Ptr CInt
307 setStepFlag = poke stepFlag 1
308 resetStepFlag = poke stepFlag 0
310 -- this points to the IO action that is executed when a breakpoint is hit
311 foreign import ccall "&rts_breakpoint_io_action"
312 breakPointIOAction :: Ptr (StablePtr (Bool -> BreakInfo -> HValue -> IO ()))
314 -- When running a computation, we redirect ^C exceptions to the running
315 -- thread. ToDo: we might want a way to continue even if the target
316 -- thread doesn't die when it receives the exception... "this thread
317 -- is not responding".
318 sandboxIO :: DynFlags -> MVar Status -> IO [HValue] -> IO Status
319 sandboxIO dflags statusMVar thing =
321 (forkIO (do res <- Exception.try (rethrow dflags thing)
322 putMVar statusMVar (Complete res)))
323 (takeMVar statusMVar)
325 -- We want to turn ^C into a break when -fbreak-on-exception is on,
326 -- but it's an async exception and we only break for sync exceptions.
327 -- Idea: if we catch and re-throw it, then the re-throw will trigger
328 -- a break. Great - but we don't want to re-throw all exceptions, because
329 -- then we'll get a double break for ordinary sync exceptions (you'd have
330 -- to :continue twice, which looks strange). So if the exception is
331 -- not "Interrupted", we unset the exception flag before throwing.
333 rethrow :: DynFlags -> IO a -> IO a
334 rethrow dflags io = Exception.catch io $ \e -> do -- NB. not catchDyn
336 -- If -fbreak-on-error, we break unconditionally,
337 -- but with care of not breaking twice
338 _ | dopt Opt_BreakOnError dflags &&
339 not(dopt Opt_BreakOnException dflags)
340 -> poke exceptionFlag 1
342 -- If it is an "Interrupted" exception, we allow
343 -- a possible break by way of -fbreak-on-exception
344 DynException d | Just Interrupted <- fromDynamic d
347 -- In any other case, we don't want to break
348 _ -> poke exceptionFlag 0
353 withInterruptsSentTo :: IO ThreadId -> IO r -> IO r
354 withInterruptsSentTo io get_result = do
355 ts <- takeMVar interruptTargetThread
357 putMVar interruptTargetThread (child:ts)
358 get_result `finally` modifyMVar_ interruptTargetThread (return.tail)
360 -- This function sets up the interpreter for catching breakpoints, and
361 -- resets everything when the computation has stopped running. This
362 -- is a not-very-good way to ensure that only the interactive
363 -- evaluation should generate breakpoints.
364 withBreakAction step dflags breakMVar statusMVar io
365 = bracket setBreakAction resetBreakAction (\_ -> io)
368 stablePtr <- newStablePtr onBreak
369 poke breakPointIOAction stablePtr
370 when (dopt Opt_BreakOnException dflags) $ poke exceptionFlag 1
371 when step $ setStepFlag
373 -- Breaking on exceptions is not enabled by default, since it
374 -- might be a bit surprising. The exception flag is turned off
375 -- as soon as it is hit, or in resetBreakAction below.
377 onBreak is_exception info apStack = do
379 putMVar statusMVar (Break is_exception apStack info tid)
382 resetBreakAction stablePtr = do
383 poke breakPointIOAction noBreakStablePtr
386 freeStablePtr stablePtr
388 noBreakStablePtr = unsafePerformIO $ newStablePtr noBreakAction
390 noBreakAction False info apStack = putStrLn "*** Ignoring breakpoint"
391 noBreakAction True info apStack = return () -- exception: just continue
393 resume :: Session -> SingleStep -> IO RunResult
394 resume (Session ref) step
396 hsc_env <- readIORef ref
397 let ic = hsc_IC hsc_env
398 resume = ic_resume ic
401 [] -> throwDyn (ProgramError "not stopped at a breakpoint")
403 -- unbind the temporary locals by restoring the TypeEnv from
404 -- before the breakpoint, and drop this Resume from the
405 -- InteractiveContext.
406 let (resume_tmp_ids, resume_tyvars) = resumeBindings r
407 ic' = ic { ic_tmp_ids = resume_tmp_ids,
408 ic_tyvars = resume_tyvars,
410 writeIORef ref hsc_env{ hsc_IC = ic' }
412 -- remove any bindings created since the breakpoint from the
413 -- linker's environment
414 let new_names = map idName (filter (`notElem` resume_tmp_ids)
416 Linker.deleteFromLinkEnv new_names
418 when (isStep step) $ setStepFlag
420 Resume expr tid breakMVar statusMVar bindings
421 final_ids apStack info _ hist _ -> do
422 withBreakAction (isStep step) (hsc_dflags hsc_env)
423 breakMVar statusMVar $ do
424 status <- withInterruptsSentTo
425 (do putMVar breakMVar ()
426 -- this awakens the stopped thread...
428 (takeMVar statusMVar)
429 -- and wait for the result
432 Nothing -> fromListBL 50 hist
433 Just i -> mkHistory hsc_env apStack i `consBL`
437 traceRunStatus expr ref bindings final_ids
438 breakMVar statusMVar status hist'
440 handleRunStatus expr ref bindings final_ids
441 breakMVar statusMVar status hist'
444 back :: Session -> IO ([Name], Int, SrcSpan)
447 forward :: Session -> IO ([Name], Int, SrcSpan)
448 forward = moveHist (subtract 1)
450 moveHist fn (Session ref) = do
451 hsc_env <- readIORef ref
452 case ic_resume (hsc_IC hsc_env) of
453 [] -> throwDyn (ProgramError "not stopped at a breakpoint")
455 let ix = resumeHistoryIx r
456 history = resumeHistory r
459 when (new_ix > length history) $
460 throwDyn (ProgramError "no more logged breakpoints")
462 throwDyn (ProgramError "already at the beginning of the history")
465 update_ic apStack mb_info = do
466 (hsc_env1, names, span) <- bindLocalsAtBreakpoint hsc_env
468 let ic = hsc_IC hsc_env1
469 r' = r { resumeHistoryIx = new_ix }
470 ic' = ic { ic_resume = r':rs }
472 writeIORef ref hsc_env1{ hsc_IC = ic' }
474 return (names, new_ix, span)
476 -- careful: we want apStack to be the AP_STACK itself, not a thunk
477 -- around it, hence the cases are carefully constructed below to
478 -- make this the case. ToDo: this is v. fragile, do something better.
481 Resume { resumeApStack = apStack,
482 resumeBreakInfo = mb_info } ->
483 update_ic apStack mb_info
484 else case history !! (new_ix - 1) of
485 History apStack info _ ->
486 update_ic apStack (Just info)
488 -- -----------------------------------------------------------------------------
489 -- After stopping at a breakpoint, add free variables to the environment
490 result_fs = FSLIT("_result")
492 bindLocalsAtBreakpoint
496 -> IO (HscEnv, [Name], SrcSpan)
498 -- Nothing case: we stopped when an exception was raised, not at a
499 -- breakpoint. We have no location information or local variables to
500 -- bind, all we can do is bind a local variable to the exception
502 bindLocalsAtBreakpoint hsc_env apStack Nothing = do
503 let exn_fs = FSLIT("_exception")
504 exn_name = mkInternalName (getUnique exn_fs) (mkVarOccFS exn_fs) span
506 e_name = mkInternalName (getUnique e_fs) (mkTyVarOcc e_fs) span
507 e_tyvar = mkTcTyVar e_name liftedTypeKind (SkolemTv RuntimeUnkSkol)
508 exn_id = Id.mkGlobalId VanillaGlobal exn_name (mkTyVarTy e_tyvar)
510 new_tyvars = unitVarSet e_tyvar
512 ictxt0 = hsc_IC hsc_env
513 ictxt1 = extendInteractiveContext ictxt0 [exn_id] new_tyvars
515 span = mkGeneralSrcSpan FSLIT("<exception thrown>")
517 Linker.extendLinkEnv [(exn_name, unsafeCoerce# apStack)]
518 return (hsc_env{ hsc_IC = ictxt1 }, [exn_name], span)
520 -- Just case: we stopped at a breakpoint, we have information about the location
521 -- of the breakpoint and the free variables of the expression.
522 bindLocalsAtBreakpoint hsc_env apStack (Just info) = do
525 mod_name = moduleName (breakInfo_module info)
526 hmi = expectJust "bindLocalsAtBreakpoint" $
527 lookupUFM (hsc_HPT hsc_env) mod_name
528 breaks = getModBreaks hmi
529 index = breakInfo_number info
530 vars = breakInfo_vars info
531 result_ty = breakInfo_resty info
532 occs = modBreaks_vars breaks ! index
533 span = modBreaks_locs breaks ! index
535 -- filter out any unboxed ids; we can't bind these at the prompt
536 let pointers = filter (\(id,_) -> isPointer id) vars
537 isPointer id | PtrRep <- idPrimRep id = True
540 let (ids, offsets) = unzip pointers
542 -- It might be that getIdValFromApStack fails, because the AP_STACK
543 -- has been accidentally evaluated, or something else has gone wrong.
544 -- So that we don't fall over in a heap when this happens, just don't
545 -- bind any free variables instead, and we emit a warning.
546 mb_hValues <- mapM (getIdValFromApStack apStack) offsets
547 let filtered_ids = [ id | (id, Just hv) <- zip ids mb_hValues ]
548 when (any isNothing mb_hValues) $
549 debugTraceMsg (hsc_dflags hsc_env) 1 $
550 text "Warning: _result has been evaluated, some bindings have been lost"
552 new_ids <- zipWithM mkNewId occs filtered_ids
553 let names = map idName new_ids
555 -- make an Id for _result. We use the Unique of the FastString "_result";
556 -- we don't care about uniqueness here, because there will only be one
557 -- _result in scope at any time.
558 let result_name = mkInternalName (getUnique result_fs)
559 (mkVarOccFS result_fs) span
560 result_id = Id.mkGlobalId VanillaGlobal result_name result_ty
563 -- for each Id we're about to bind in the local envt:
564 -- - skolemise the type variables in its type, so they can't
565 -- be randomly unified with other types. These type variables
566 -- can only be resolved by type reconstruction in RtClosureInspect
567 -- - tidy the type variables
568 -- - globalise the Id (Ids are supposed to be Global, apparently).
570 let all_ids | isPointer result_id = result_id : new_ids
571 | otherwise = new_ids
572 (id_tys, tyvarss) = mapAndUnzip (skolemiseTy.idType) all_ids
573 (_,tidy_tys) = tidyOpenTypes emptyTidyEnv id_tys
574 new_tyvars = unionVarSets tyvarss
575 let final_ids = zipWith setIdType all_ids tidy_tys
576 ictxt0 = hsc_IC hsc_env
577 ictxt1 = extendInteractiveContext ictxt0 final_ids new_tyvars
578 Linker.extendLinkEnv [ (name,hval) | (name, Just hval) <- zip names mb_hValues ]
579 Linker.extendLinkEnv [(result_name, unsafeCoerce# apStack)]
580 hsc_env1 <- rttiEnvironment hsc_env{ hsc_IC = ictxt1 }
581 return (hsc_env1, result_name:names, span)
583 mkNewId :: OccName -> Id -> IO Id
585 let uniq = idUnique id
586 loc = nameSrcSpan (idName id)
587 name = mkInternalName uniq occ loc
589 new_id = Id.mkGlobalId VanillaGlobal name ty (idInfo id)
592 rttiEnvironment :: HscEnv -> IO HscEnv
593 rttiEnvironment hsc_env@HscEnv{hsc_IC=ic} = do
594 let InteractiveContext{ic_tmp_ids=tmp_ids} = ic
595 incompletelyTypedIds =
597 , not $ null [v | v <- varSetElems$ tyVarsOfType (idType id)
599 , (occNameFS.nameOccName.idName) id /= result_fs]
600 tys <- reconstructType hsc_env 10 `mapM` incompletelyTypedIds
601 -- map termType `fmap` (obtainTerm hsc_env False `mapM` incompletelyTypedIds)
603 let substs = [computeRTTIsubst ty ty'
604 | (ty, Just ty') <- zip (map idType incompletelyTypedIds) tys]
605 ic' = foldr (flip substInteractiveContext) ic
606 (map skolemiseSubst $ catMaybes substs)
607 return hsc_env{hsc_IC=ic'}
609 skolemiseSubst subst = subst `setTvSubstEnv`
610 mapVarEnv (fst.skolemiseTy) (getTvSubstEnv subst)
612 skolemiseTy :: Type -> (Type, TyVarSet)
613 skolemiseTy ty = (substTy subst ty, mkVarSet new_tyvars)
614 where env = mkVarEnv (zip tyvars new_tyvar_tys)
615 subst = mkTvSubst emptyInScopeSet env
616 tyvars = varSetElems (tyVarsOfType ty)
617 new_tyvars = map skolemiseTyVar tyvars
618 new_tyvar_tys = map mkTyVarTy new_tyvars
620 skolemiseTyVar :: TyVar -> TyVar
621 skolemiseTyVar tyvar = mkTcTyVar (tyVarName tyvar) (tyVarKind tyvar)
622 (SkolemTv RuntimeUnkSkol)
624 getIdValFromApStack :: HValue -> Int -> IO (Maybe HValue)
625 getIdValFromApStack apStack (I# stackDepth) = do
626 case getApStackVal# apStack (stackDepth +# 1#) of
627 -- The +1 is magic! I don't know where it comes
628 -- from, but this makes things line up. --SDM
631 0# -> return Nothing -- AP_STACK not found
632 _ -> return (Just (unsafeCoerce# result))
634 pushResume :: HscEnv -> Resume -> HscEnv
635 pushResume hsc_env resume = hsc_env { hsc_IC = ictxt1 }
637 ictxt0 = hsc_IC hsc_env
638 ictxt1 = ictxt0 { ic_resume = resume : ic_resume ictxt0 }
640 -- -----------------------------------------------------------------------------
641 -- Abandoning a resume context
643 abandon :: Session -> IO Bool
644 abandon (Session ref) = do
645 hsc_env <- readIORef ref
646 let ic = hsc_IC hsc_env
647 resume = ic_resume ic
651 writeIORef ref hsc_env{ hsc_IC = ic { ic_resume = rs } }
655 abandonAll :: Session -> IO Bool
656 abandonAll (Session ref) = do
657 hsc_env <- readIORef ref
658 let ic = hsc_IC hsc_env
659 resume = ic_resume ic
663 writeIORef ref hsc_env{ hsc_IC = ic { ic_resume = [] } }
667 -- when abandoning a computation we have to
668 -- (a) kill the thread with an async exception, so that the
669 -- computation itself is stopped, and
670 -- (b) fill in the MVar. This step is necessary because any
671 -- thunks that were under evaluation will now be updated
672 -- with the partial computation, which still ends in takeMVar,
673 -- so any attempt to evaluate one of these thunks will block
674 -- unless we fill in the MVar.
675 -- See test break010.
676 abandon_ :: Resume -> IO ()
678 killThread (resumeThreadId r)
679 putMVar (resumeBreakMVar r) ()
681 -- -----------------------------------------------------------------------------
682 -- Bounded list, optimised for repeated cons
684 data BoundedList a = BL
685 {-# UNPACK #-} !Int -- length
686 {-# UNPACK #-} !Int -- bound
688 [a] -- right, list is (left ++ reverse right)
690 nilBL :: Int -> BoundedList a
691 nilBL bound = BL 0 bound [] []
693 consBL a (BL len bound left right)
694 | len < bound = BL (len+1) bound (a:left) right
695 | null right = BL len bound [a] $! tail (reverse left)
696 | otherwise = BL len bound (a:left) $! tail right
698 toListBL (BL _ _ left right) = left ++ reverse right
700 fromListBL bound l = BL (length l) bound l []
702 -- lenBL (BL len _ _ _) = len
704 -- -----------------------------------------------------------------------------
705 -- | Set the interactive evaluation context.
707 -- Setting the context doesn't throw away any bindings; the bindings
708 -- we've built up in the InteractiveContext simply move to the new
709 -- module. They always shadow anything in scope in the current context.
710 setContext :: Session
711 -> [Module] -- entire top level scope of these modules
712 -> [Module] -- exports only of these modules
714 setContext sess@(Session ref) toplev_mods export_mods = do
715 hsc_env <- readIORef ref
716 let old_ic = hsc_IC hsc_env
717 hpt = hsc_HPT hsc_env
719 export_env <- mkExportEnv hsc_env export_mods
720 toplev_envs <- mapM (mkTopLevEnv hpt) toplev_mods
721 let all_env = foldr plusGlobalRdrEnv export_env toplev_envs
722 writeIORef ref hsc_env{ hsc_IC = old_ic { ic_toplev_scope = toplev_mods,
723 ic_exports = export_mods,
724 ic_rn_gbl_env = all_env }}
726 -- Make a GlobalRdrEnv based on the exports of the modules only.
727 mkExportEnv :: HscEnv -> [Module] -> IO GlobalRdrEnv
728 mkExportEnv hsc_env mods = do
729 stuff <- mapM (getModuleExports hsc_env) mods
731 (_msgs, mb_name_sets) = unzip stuff
732 gres = [ nameSetToGlobalRdrEnv (availsToNameSet avails) (moduleName mod)
733 | (Just avails, mod) <- zip mb_name_sets mods ]
735 return $! foldr plusGlobalRdrEnv emptyGlobalRdrEnv gres
737 nameSetToGlobalRdrEnv :: NameSet -> ModuleName -> GlobalRdrEnv
738 nameSetToGlobalRdrEnv names mod =
739 mkGlobalRdrEnv [ GRE { gre_name = name, gre_par = NoParent, gre_prov = vanillaProv mod }
740 | name <- nameSetToList names ]
742 vanillaProv :: ModuleName -> Provenance
743 -- We're building a GlobalRdrEnv as if the user imported
744 -- all the specified modules into the global interactive module
745 vanillaProv mod_name = Imported [ImpSpec { is_decl = decl, is_item = ImpAll}]
747 decl = ImpDeclSpec { is_mod = mod_name, is_as = mod_name,
749 is_dloc = srcLocSpan interactiveSrcLoc }
751 mkTopLevEnv :: HomePackageTable -> Module -> IO GlobalRdrEnv
753 = case lookupUFM hpt (moduleName modl) of
754 Nothing -> throwDyn (ProgramError ("mkTopLevEnv: not a home module " ++
755 showSDoc (ppr modl)))
757 case mi_globals (hm_iface details) of
759 throwDyn (ProgramError ("mkTopLevEnv: not interpreted "
760 ++ showSDoc (ppr modl)))
761 Just env -> return env
763 -- | Get the interactive evaluation context, consisting of a pair of the
764 -- set of modules from which we take the full top-level scope, and the set
765 -- of modules from which we take just the exports respectively.
766 getContext :: Session -> IO ([Module],[Module])
767 getContext s = withSession s (\HscEnv{ hsc_IC=ic } ->
768 return (ic_toplev_scope ic, ic_exports ic))
770 -- | Returns 'True' if the specified module is interpreted, and hence has
771 -- its full top-level scope available.
772 moduleIsInterpreted :: Session -> Module -> IO Bool
773 moduleIsInterpreted s modl = withSession s $ \h ->
774 if modulePackageId modl /= thisPackage (hsc_dflags h)
776 else case lookupUFM (hsc_HPT h) (moduleName modl) of
777 Just details -> return (isJust (mi_globals (hm_iface details)))
778 _not_a_home_module -> return False
780 -- | Looks up an identifier in the current interactive context (for :info)
781 -- Filter the instances by the ones whose tycons (or clases resp)
782 -- are in scope (qualified or otherwise). Otherwise we list a whole lot too many!
783 -- The exact choice of which ones to show, and which to hide, is a judgement call.
785 getInfo :: Session -> Name -> IO (Maybe (TyThing,Fixity,[Instance]))
787 = withSession s $ \hsc_env ->
788 do { mb_stuff <- tcRnGetInfo hsc_env name
790 Nothing -> return Nothing
791 Just (thing, fixity, ispecs) -> do
792 { let rdr_env = ic_rn_gbl_env (hsc_IC hsc_env)
793 ; return (Just (thing, fixity, filter (plausible rdr_env) ispecs)) } }
795 plausible rdr_env ispec -- Dfun involving only names that are in ic_rn_glb_env
796 = all ok $ nameSetToList $ tyClsNamesOfType $ idType $ instanceDFunId ispec
797 where -- A name is ok if it's in the rdr_env,
798 -- whether qualified or not
799 ok n | n == name = True -- The one we looked for in the first place!
800 | isBuiltInSyntax n = True
801 | isExternalName n = any ((== n) . gre_name)
802 (lookupGRE_Name rdr_env n)
805 -- | Returns all names in scope in the current interactive context
806 getNamesInScope :: Session -> IO [Name]
807 getNamesInScope s = withSession s $ \hsc_env -> do
808 return (map gre_name (globalRdrEnvElts (ic_rn_gbl_env (hsc_IC hsc_env))))
810 getRdrNamesInScope :: Session -> IO [RdrName]
811 getRdrNamesInScope s = withSession s $ \hsc_env -> do
814 gbl_rdrenv = ic_rn_gbl_env ic
816 gbl_names = concat (map greToRdrNames (globalRdrEnvElts gbl_rdrenv))
817 lcl_names = map (mkRdrUnqual.nameOccName.idName) ids
819 return (gbl_names ++ lcl_names)
822 -- ToDo: move to RdrName
823 greToRdrNames :: GlobalRdrElt -> [RdrName]
824 greToRdrNames GRE{ gre_name = name, gre_prov = prov }
827 Imported specs -> concat (map do_spec (map is_decl specs))
829 occ = nameOccName name
832 | is_qual decl_spec = [qual]
833 | otherwise = [unqual,qual]
834 where qual = Qual (is_as decl_spec) occ
836 -- | Parses a string as an identifier, and returns the list of 'Name's that
837 -- the identifier can refer to in the current interactive context.
838 parseName :: Session -> String -> IO [Name]
839 parseName s str = withSession s $ \hsc_env -> do
840 maybe_rdr_name <- hscParseIdentifier (hsc_dflags hsc_env) str
841 case maybe_rdr_name of
843 Just (L _ rdr_name) -> do
844 mb_names <- tcRnLookupRdrName hsc_env rdr_name
848 -- ToDo: should return error messages
850 -- | Returns the 'TyThing' for a 'Name'. The 'Name' may refer to any
851 -- entity known to GHC, including 'Name's defined using 'runStmt'.
852 lookupName :: Session -> Name -> IO (Maybe TyThing)
853 lookupName s name = withSession s $ \hsc_env -> tcRnLookupName hsc_env name
855 -- -----------------------------------------------------------------------------
856 -- Getting the type of an expression
858 -- | Get the type of an expression
859 exprType :: Session -> String -> IO (Maybe Type)
860 exprType s expr = withSession s $ \hsc_env -> do
861 maybe_stuff <- hscTcExpr hsc_env expr
863 Nothing -> return Nothing
864 Just ty -> return (Just tidy_ty)
866 tidy_ty = tidyType emptyTidyEnv ty
868 -- -----------------------------------------------------------------------------
869 -- Getting the kind of a type
871 -- | Get the kind of a type
872 typeKind :: Session -> String -> IO (Maybe Kind)
873 typeKind s str = withSession s $ \hsc_env -> do
874 maybe_stuff <- hscKcType hsc_env str
876 Nothing -> return Nothing
877 Just kind -> return (Just kind)
879 -----------------------------------------------------------------------------
880 -- cmCompileExpr: compile an expression and deliver an HValue
882 compileExpr :: Session -> String -> IO (Maybe HValue)
883 compileExpr s expr = withSession s $ \hsc_env -> do
884 maybe_stuff <- hscStmt hsc_env ("let __cmCompileExpr = "++expr)
886 Nothing -> return Nothing
887 Just (ids, hval) -> do
889 hvals <- (unsafeCoerce# hval) :: IO [HValue]
892 ([n],[hv]) -> return (Just hv)
893 _ -> panic "compileExpr"
895 -- -----------------------------------------------------------------------------
896 -- Compile an expression into a dynamic
898 dynCompileExpr :: Session -> String -> IO (Maybe Dynamic)
899 dynCompileExpr ses expr = do
900 (full,exports) <- getContext ses
901 setContext ses full $
903 (stringToPackageId "base") (mkModuleName "Data.Dynamic")
905 let stmt = "let __dynCompileExpr = Data.Dynamic.toDyn (" ++ expr ++ ")"
906 res <- withSession ses (flip hscStmt stmt)
907 setContext ses full exports
909 Nothing -> return Nothing
910 Just (ids, hvals) -> do
911 vals <- (unsafeCoerce# hvals :: IO [Dynamic])
913 (_:[], v:[]) -> return (Just v)
914 _ -> panic "dynCompileExpr"
916 -----------------------------------------------------------------------------
917 -- show a module and it's source/object filenames
919 showModule :: Session -> ModSummary -> IO String
920 showModule s mod_summary = withSession s $ \hsc_env ->
921 isModuleInterpreted s mod_summary >>= \interpreted ->
922 return (showModMsg (hscTarget(hsc_dflags hsc_env)) interpreted mod_summary)
924 isModuleInterpreted :: Session -> ModSummary -> IO Bool
925 isModuleInterpreted s mod_summary = withSession s $ \hsc_env ->
926 case lookupUFM (hsc_HPT hsc_env) (ms_mod_name mod_summary) of
927 Nothing -> panic "missing linkable"
928 Just mod_info -> return (not obj_linkable)
930 obj_linkable = isObjectLinkable (expectJust "showModule" (hm_linkable mod_info))
932 ----------------------------------------------------------------------------
935 obtainTerm1 :: HscEnv -> Bool -> Maybe Type -> a -> IO Term
936 obtainTerm1 hsc_env force mb_ty x =
937 cvObtainTerm hsc_env maxBound force mb_ty (unsafeCoerce# x)
939 obtainTermB :: HscEnv -> Int -> Bool -> Id -> IO Term
940 obtainTermB hsc_env bound force id = do
941 hv <- Linker.getHValue hsc_env (varName id)
942 cvObtainTerm hsc_env bound force (Just$ idType id) hv
944 obtainTerm :: HscEnv -> Bool -> Id -> IO Term
945 obtainTerm hsc_env force id = do
946 hv <- Linker.getHValue hsc_env (varName id)
947 cvObtainTerm hsc_env maxBound force (Just$ idType id) hv
949 -- Uses RTTI to reconstruct the type of an Id, making it less polymorphic
950 reconstructType :: HscEnv -> Int -> Id -> IO (Maybe Type)
951 reconstructType hsc_env bound id = do
952 hv <- Linker.getHValue hsc_env (varName id)
953 cvReconstructType hsc_env bound (Just$ idType id) hv